Nineteen year-old Hanson, who can play as a centre half or right back, has signed a two-and-a-half year deal at the Northern Commercials Stadium after moving from West Yorkshire neighbours Huddersfield Town for an undisclosed fee.
Left back Penney, who turns 19 himself in February, has penned a loan deal from Sheffield Wednesday that will keep him with Stuart McCall's squad until the end of the current 2016/2017 season.
Hanson (pictured right) will wear squad number 16, while Penney has been allocated the number 17 shirt.
Nicknamed 'Jabba', Hanson is known for his lightning pace and direct playing style.
After coming through the ranks with the Terriers, Hanson signed a professional deal at the John Smith's Stadium back in March 2015.
Penney (pictured left) arrives at Valley Parade with a reputation for great technique, not to mention an eye for a spectacular goal or two, on his favoured left foot.
Chesterfield-born Penney joined the Owls' youth set-up aged just eight years-old and signed a professional contract at Hillsborough in October 2015.
Speaking about the two new recruits, Head of Recruitment Greg Abbott said: "Jacob is a very versatile defender - he can play in a number of positions - while Matt will offer us cover at left back.
"Jacob is a player we have brought in as we feel he can develop with us going forward.
"He will give us some squad cover for this season, but he is also someone we can see progressing nicely for the future. He is very quick and a great athlete.
"Matt has a great left foot on him. He is a threat on set-pieces and also has bags of pace himself.
"They are both players who can add depth to our squad for the remainder of the season.
"They are also two exciting young players who we hope can give us more than that going forward, certainly in the case of Jacob."